As is known in the art, for receive operations in an optical transmit-receive system, such as an optical communications system for example, phase wavefronts are uniform when entering an array of optical apertures and receive paths of the system function to provide minute adjustments to compensate for phase errors in the receive path. By compensating for phase errors, it is possible to maximize the power into a receiver.
During a transmit operation, a coherent source provides an optical transmit signal (e.g. an optical communication signal) which is divided among, and emitted through, a plurality of optical apertures. Ideally, the transmit signals exit each aperture in phase such that the phase wavefronts form a plane. One difficulty with the transmit operation, however, is the ability to dynamically and continuously measure and compensate for aperture-to-aperture wavefront errors (including overall, or “piston”, phase errors) in a manner which allows the system to meet certain requirements regarding coherence of transmit signals while at the same time staying within desired size, weight and power (SWaP) constraints. In a communications system, for example, a system must meet certain requirements to achieve adequate link margin while at the same time staying within designated SWaP constraints of an operational platform.